A novel double hemizygous BTK mutation in a boy presenting with Pseudomonas skin abscesses.

Skin manifestations can serve as critical clues for early diagnosis of inborn errors of immunity. We report a patient with a double novel mutation in the BTK gene, who presented with skin abscesses caused by Pseudomonas aeruginosa. This case illustrates the importance of immune evaluation in patients with therapy-resistant skin lesions.

Pulp chamber features, prevalence of abscesses, disease severity, and PHEX mutation in X-linked hypophosphatemic rickets.

INTRODUCTION: Rickets, growth failure, and recurrent periapical abscesses with fistulae are main signs in patients with X-linked hypophosphatemic rickets (XLH). Prevalence of abscesses, pulp chamber features, biochemical findings, disease severity, and PHEX gene mutation were examined. MATERIALS AND METHODS: Pulp chambers size, shape, and morphology were assessed by orthopantomography in XLH patients (n = 24, age 5.8 ± 1.6 years) and in sex and age-matched healthy controls (n = 23, age 6.2 ± 1.4 years). XLH patients received conventional treatment (3.5 ± 1.9 years). Pulp chamber features were assessed in teeth of primary dentition and in the permanent left mandibular first molar and compared with those of controls. Rickets severity score was assessed at wrist, knee, and ankle. RESULTS: The mean pulp chamber area/tooth area ratio, mean pulp chamber height/pulp chamber width ratio, and prominence of pulp horns into the tooth crown in primary and secondary molars were significantly higher in patients than in controls and in patients suffered abscesses than in patients without abscesses. Sixteen patients (67%) had a history of abscesses; incisors were affected more than canines and molars. Severity of rickets and mean serum parathyroid hormone (PTH) levels were significantly higher, and mean serum 1,25-dihydroxyvitamin D [1,25(OH)2D] levels significantly lower in patients suffered abscesses than in patients without abscesses. PHEX gene mutations were not correlated with dental phenotype and disease severity. CONCLUSION: Enlarged pulp chambers with altered shape and morphology affected the majority of XLH patients predisposing to recurrent periapical abscesses with fistulae. Dental phenotype was associated with severity of rickets, high serum PTH, and low serum 1,25(OH)2D levels.

Macrophage-derived LTB4 promotes abscess formation and clearance of Staphylococcus aureus skin infection in mice.

The early events that shape the innate immune response to restrain pathogens during skin infections remain elusive. Methicillin-resistant Staphylococcus aureus (MRSA) infection engages phagocyte chemotaxis, abscess formation, and microbial clearance. Upon infection, neutrophils and monocytes find a gradient of chemoattractants that influence both phagocyte direction and microbial clearance. The bioactive lipid leukotriene B4 (LTB4) is quickly (seconds to minutes) produced by 5-lipoxygenase (5-LO) and signals through the G protein-coupled receptors LTB4R1 (BLT1) or BLT2 in phagocytes and structural cells. Although it is known that LTB4 enhances antimicrobial effector functions in vitro, whether prompt LTB4 production is required for bacterial clearance and development of an inflammatory milieu necessary for abscess formation to restrain pathogen dissemination is unknown. We found that LTB4 is produced in areas near the abscess and BLT1 deficient mice are unable to form an abscess, elicit neutrophil chemotaxis, generation of neutrophil and monocyte chemokines, as well as reactive oxygen species-dependent bacterial clearance. We also found that an ointment containing LTB4 synergizes with antibiotics to eliminate MRSA potently. Here, we uncovered a heretofore unknown role of macrophage-derived LTB4 in orchestrating the chemoattractant gradient required for abscess formation, while amplifying antimicrobial effector functions.

Recurrent sterile abscesses in a case of X-linked neutropenia.

Cutaneous manifestations are common in monogenic immune disorders, including both infectious and non-infectious etiologies. We report follow-up of a case initially published in Pediatric Dermatology in 2001 of a 13-year-old boy with a history of inflammatory skin lesions and neutropenia who developed neutrophilic dermatoses precipitated by G-CSF. Whole exome sequencing performed at 36 years of age revealed a gain-of-function mutation in the WAS gene, leading to a diagnosis of X-linked neutropenia. This case report provides closure on a decades-long diagnostic odyssey and underscores the importance of genetic sequencing in patients who present with unusual dermatologic findings.

Rs531564 polymorphism in microRNA-214 regulates interleukin-6R expression in anal fissure patients to affect the risk of anal abscess formation.

BACKGROUND: Anal abscess is an important complication of anal fissure (AF), whereas interleukin-6R (IL-6R) has been implicated in the development of abscess. In this study, we aimed to explore the possible molecular mechanisms underlying the regulatory effects of miRNAs on IL-6R and other inflammatory factors related to the induction of anal abscess in AF. METHODS: Bioinformatics analysis, luciferase assay, real-time polymerase chain reaction, and Western blot analysis were performed to identify the possible regulatory relationships between IL-6R and miR-124/miR-125a by comparing the differentiated expression of miR-125a, miR-124, tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), and IL-4 among different groups of AF patients. RESULTS: IL-6R messenger RNA (mRNA) was identified as a target gene of miR-124 because the luciferase activity in cells cotransfected with wild-type IL-6R and miR-124 mimics was significantly reduced. In addition, the expression of IL-6R mRNA and protein was significantly inhibited in the presence of miR-124 or an IL-6R inhibitor, confirming the presence of a negative regulatory relationship between miR-124 and IL-6R. Moreover, miR-124 and inflammatory factors were differentially expressed in AF patients carrying different genotypes of rs531564 polymorphism. CONCLUSIONS: miR-124 and inflammatory factors TNF-α, IFN-γ, and IL-4 may be used as indicators of anal abscess development in AF patients. In addition, miR-124 polymorphism rs531564 is involved with the pathogenesis of anal abscess in AF patients, and the presence of rs531564 may increase the incidence of anal abscess via upregulating the expression of IL-6R, TNF-α, IFN-γ, and IL-4.

Lack of Receptor for Advanced Glycation End Products Leads to Less Severe Staphylococcal Skin Infection but More Skin Abscesses and Prolonged Wound Healing.

Background: Lack of receptor for advanced glycation end products (RAGE) ameliorates several infections including Staphylococcus aureus pneumonia. We sought to investigate the role of RAGE in staphylococcal skin infection in mice. Methods: Wild-type (WT) and RAGE deficient (RAGE-/-) mice were subcutaneously inoculated with S. aureus SH1000 strain in abscess-forming dose or necrotic dose. Clinical signs of dermatitis, along with histopathological changes, were compared between the groups. Results: The skin lesion size was smaller in RAGE-/- mice. Infected RAGE-/- mice expressed lower proinflammatory cytokines in local skins compared to control mice. Low dose of bacteria caused more abscess formation in RAGE-/- mice compared to skin necrosis that was more often observed in WT mice. As a result of more abscess formation, the wound healing was prolonged in RAGE-/- mice. Importantly, RAGE-/- mice had lower bacterial loads in the skin than controls, which is correlated with higher local levels of myeloperoxidase before skin infection. In vitro, enhanced phagocytic capacity of neutrophils and macrophages obtained from RAGE-/- mice compared to control mice was observed. Conclusions: RAGE deficiency up-regulates phagocytic capacity of phagocytes, resulting in lower bacterial burden in local skin and milder skin lesions in mice with staphylococcal skin infection.

MyD88 in macrophages is critical for abscess resolution in staphylococcal skin infection.

When Staphylococcus aureus penetrates the epidermis and reaches the dermis, polymorphonuclear leukocytes (PMLs) accumulate and an abscess is formed. However, the molecular mechanisms that orchestrate initiation and termination of inflammation in skin infection are incompletely understood. In human myeloid differentiation primary response gene 88 (MyD88) deficiency, staphylococcal skin and soft tissue infections are a leading and potentially life-threatening problem. In this study, we found that MyD88-dependent sensing of S. aureus by dermal macrophages (Mϕ) contributes to both timely escalation and termination of PML-mediated inflammation in a mouse model of staphylococcal skin infection. Mϕs were key to recruit PML within hours in response to staphylococci, irrespective of bacterial viability. In contrast with bone marrow-derived Mϕs, dermal Mϕs did not require UNC-93B or TLR2 for activation. Moreover, PMLs, once recruited, were highly activated in an MyD88-independent fashion, yet failed to clear the infection if Mϕs were missing or functionally impaired. In normal mice, clearance of the infection and contraction of the PML infiltrate were accompanied by expansion of resident Mϕs in a CCR2-dependent fashion. Thus, whereas monocytes were dispensable for the early immune response to staphylococci, they contributed to Mϕ renewal after the infection was overcome. Taken together, MyD88-dependent sensing of staphylococci by resident dermal Mϕs is key for a rapid and balanced immune response, and PMLs are dependent on intact Mϕ for full function. Renewal of resident Mϕs requires both local control of bacteria and inflammatory monocytes entering the skin.

MICA*A4 protects against ulcerative colitis, whereas MICA*A5.1 is associated with abscess formation and age of onset.

Ulcerative colitis (UC) is one of the two major forms of inflammatory bowel disease, the aetiology of which remains unknown. Several studies have demonstrated the genetic basis of disease, identifying more than 130 susceptibility loci. The major histocompatibility complex class I chain-related gene A (MICA) is a useful candidate to be involved in UC pathogenesis, because it could be important in recognizing the integrity of the epithelial cell and its response to stress. The aim of this study was to analyse the relationship between polymorphisms in the transmembrane domain of MICA and susceptibility to develop UC. A total of 340 patients with UC and 636 healthy controls were genotyped for MICA transmembrane polymorphism using a polymerase chain reaction (PCR) combined with fluorescent technology. Different MICA alleles were determined depending on the PCR product size. The allele MICA*A4 was less frequent in patients than in controls (P = 0·003; OR = 0·643), and this protective role is higher when it forms haplotype with B*27 (P = 0·002; OR = 0·294). The haplotype HLA-B*52/MICA*A6 was also associated with UC [P = 0·001; odds ratio (OR) = 2·914]. No other alleles, genotypes or haplotypes were related with UC risk. Moreover, MICA*A5.1 is associated independently with abscesses (P = 0·002; OR = 3·096) and its frequency is lower in patients diagnosed between ages 17 and 40 years (P = 0·007; OR = 0·633), meaning an extreme age on onset. No association with location, extra-intestinal manifestations or need for surgery was found.

Clinical and Genotypic Spectrum of Chronic Granulomatous Disease in 71 Latin American Patients: First Report from the LASID Registry.

AIM: We analyzed data from 71 patients with chronic granulomatous disease (CGD) with a confirmed genetic diagnosis, registered in the online Latin American Society of Primary Immunodeficiencies (LASID) database. RESULTS: Latin American CGD patients presented with recurrent and severe infections caused by several organisms. The mean age at disease onset was 23.9 months, and the mean age at CGD diagnosis was 52.7 months. Recurrent pneumonia was the most frequent clinical condition (76.8%), followed by lymphadenopathy (59.4%), granulomata (49.3%), skin infections (42%), chronic diarrhea (41.9%), otitis (29%), sepsis (23.2%), abscesses (21.7%), recurrent urinary tract infection (20.3%), and osteomyelitis (15.9%). Adverse reactions to bacillus Calmette-Guérin (BCG) vaccination were identified in 30% of the studied Latin American CGD cases. The genetic diagnoses of the 71 patients revealed 53 patients from 47 families with heterogeneous mutations in the CYBB gene (five novel mutations: p.W361G, p.C282X, p.W483R, p.R226X, and p.Q93X), 16 patients with the common deletion c.75_76 del.GT in exon 2 of NCF1 gene, and two patients with mutations in the CYBA gene. CONCLUSION: The majority of Latin American CGD patients carry a hemizygous mutation in the CYBB gene. They also presented a wide range of clinical manifestations most frequently bacterial and fungal infections of the respiratory tract, skin, and lymph nodes. Thirty percent of the Latin American CGD patients presented adverse reactions to BCG, indicating that this vaccine should be avoided in these patients.

Methicillin-resistant Staphylococcus aureus bacterial nitric-oxide synthase affects antibiotic sensitivity and skin abscess development.

Staphylococcus aureus infections present an enormous global health concern complicated by an alarming increase in antibiotic resistance. S. aureus is among the few bacterial species that express nitric-oxide synthase (bNOS) and thus can catalyze NO production from L-arginine. Here we generate an isogenic bNOS-deficient mutant in the epidemic community-acquired methicillin-resistant S. aureus (MRSA) USA300 clone to study its contribution to virulence and antibiotic susceptibility. Loss of bNOS increased MRSA susceptibility to reactive oxygen species and host cathelicidin antimicrobial peptides, which correlated with increased MRSA killing by human neutrophils and within neutrophil extracellular traps. bNOS also promoted resistance to the pharmaceutical antibiotics that act on the cell envelope such as vancomycin and daptomycin. Surprisingly, bNOS-deficient strains gained resistance to aminoglycosides, suggesting that the role of bNOS in antibiotic susceptibility is more complex than previously observed in Bacillus species. Finally, the MRSA bNOS mutant showed reduced virulence with decreased survival and smaller abscess generation in a mouse subcutaneous infection model. Together, these data indicate that bNOS contributes to MRSA innate immune and antibiotic resistance phenotypes. Future development of specific bNOS inhibitors could be an attractive option to simultaneously reduce MRSA pathology and enhance its susceptibility to commonly used antibiotics.

CcpA regulates arginine biosynthesis in Staphylococcus aureus through repression of proline catabolism.

Staphylococcus aureus is a leading cause of community-associated and nosocomial infections. Imperative to the success of S. aureus is the ability to adapt and utilize nutrients that are readily available. Genomic sequencing suggests that S. aureus has the genes required for synthesis of all twenty amino acids. However, in vitro experimentation demonstrates that staphylococci have multiple amino acid auxotrophies, including arginine. Although S. aureus possesses the highly conserved anabolic pathway that synthesizes arginine via glutamate, we demonstrate here that inactivation of ccpA facilitates the synthesis of arginine via the urea cycle utilizing proline as a substrate. Mutations within putA, rocD, arcB1, argG and argH abolished the ability of S. aureus JE2 ccpA::tetL to grow in the absence of arginine, whereas an interruption in argJBCF, arcB2, or proC had no effect. Furthermore, nuclear magnetic resonance demonstrated that JE2 ccpA::ermB produced (13)C(5) labeled arginine when grown with (13)C(5) proline. Taken together, these data support the conclusion that S. aureus synthesizes arginine from proline during growth on secondary carbon sources. Furthermore, although highly conserved in all sequenced S. aureus genomes, the arginine anabolic pathway (ArgJBCDFGH) is not functional under in vitro growth conditions. Finally, a mutation in argH attenuated virulence in a mouse kidney abscess model in comparison to wild type JE2 demonstrating the importance of arginine biosynthesis in vivo via the urea cycle. However, mutations in argB, argF, and putA did not attenuate virulence suggesting both the glutamate and proline pathways are active and they, or their pathway intermediates, can complement each other in vivo.

Neutrophil-derived IL-1ß is sufficient for abscess formation in immunity against Staphylococcus aureus in mice.

Neutrophil abscess formation is critical in innate immunity against many pathogens. Here, the mechanism of neutrophil abscess formation was investigated using a mouse model of Staphylococcus aureus cutaneous infection. Gene expression analysis and in vivo multispectral noninvasive imaging during the S. aureus infection revealed a strong functional and temporal association between neutrophil recruitment and IL-1ß/IL-1R activation. Unexpectedly, neutrophils but not monocytes/macrophages or other MHCII-expressing antigen presenting cells were the predominant source of IL-1ß at the site of infection. Furthermore, neutrophil-derived IL-1ß was essential for host defense since adoptive transfer of IL-1ß-expressing neutrophils was sufficient to restore the impaired neutrophil abscess formation in S. aureus-infected IL-1ß-deficient mice. S. aureus-induced IL-1ß production by neutrophils required TLR2, NOD2, FPR1 and the ASC/NLRP3 inflammasome in an α-toxin-dependent mechanism. Taken together, IL-1ß and neutrophil abscess formation during an infection are functionally, temporally and spatially linked as a consequence of direct IL-1ß production by neutrophils.

Identification of a novel STAT3 mutation in a patient with hyper-IgE syndrome.

Here we describe a patient with hyper-IgE syndrome presenting with recurrent staphylococcal abscesses, pneumonia, and chronic mucocutaneous candidiasis, and report the identification of a novel STAT3 mutation at amino acid position 621, which has not previously been described. In addition, we review the immunological, infectious, and genetic features of hyper-IgE syndrome.

Mutation in TAGAP is protective of anal sepsis in ileocolic Crohn's disease.

BACKGROUND: Anal complications of Crohn's disease range from painless skin tags to debilitating fistulas that are imperfectly treated with tumor necrosis factor antagonists. The recent discovery of more than 190 single-nucleotide polymorphisms associated with Crohn's disease offers the opportunity to genetically define the severity of anal disease in Crohn's disease and possibly predict prognosis and anti-tumor necrosis factor response. OBJECTIVES: This study aimed to identify single nucleotide polymorphisms associated with anal disease generally, septic anal disease specifically and the responsivity to anti-tumor necrosis factor treatment. DESIGN: All patients with ileocolonic Crohn's disease were identified from our IBD registry. One hundred ninety-six Crohn's disease-related single-nucleotide polymorphisms were analyzed by the use of a custom microarray chip. Patients' response to anti-tumor necrosis factor treatment was then assessed. RESULTS: One hundred sixteen patients with ileocolonic Crohn's disease were identified and assigned to septic anal disease (abscesses/fistulas, n = 35), benign anal disease (skin tags/fissures/isolated pain, n = 17), and no anal disease (n = 64) cohorts. Single-nucleotide polymorphism rs212388 negatively correlated with the presence of anal disease overall and septic disease specifically. The presence of the non-wild-type allele 'G' was protective of anal sepsis with homo- and heterozygotes having a 75% chance of no anal disease (p = 0.0001). The homozygous wild-type group had the highest risk of septic disease and included 3 of 4 patients requiring diverting ileostomies. Twenty-four patients were treated with anti-tumor necrosis factors. Nine had a beneficial response (assessed at >6 months); however, no single-nucleotide polymorphism correlated with anti-tumor necrosis factor response. Rs212388 is associated with the TAGAP molecule involved in T-cell activation. CONCLUSIONS: Rs212388 most significantly correlated with the presence and severity of anal disease in ileocolonic Crohn's disease. A single copy of the risk allele was protective, whereas wild-type homozygotes had the highest risk of septic disease and stoma creation. In this select group, no single-nucleotide polymorphism was predictive of anti-tumor necrosis factor response. Mutations in TAGAP may predict a more benign form and course of anal disease in Crohn's disease.

SNP rs322931 (C>T) in miR-181b and rs7158663 (G>A) in MEG3 aggravate the inflammatory response of anal abscess in patients with Crohn's disease.

BACKGROUND: The MEG3/miR-181b signaling has been implicated in the pathogenesis of several diseases including Crohn's disease. This work aimed to study the correlation between SNPs in MEG3/miR-181b and the severity of anal abscess in patients with Crohn's disease. METHODS: Quantitative real-time PCR was performed to analyze the expression of MEG3 and miR-181b. ELISA was carried out to examine the expression of TNF-α, IL-1ß, IL-6, CRP, SSA, AAT, AAG and HPT in the peripheral blood of patients with Crohn's disease. Luciferase assay was performed to explore the role of miR-181b in the expression of MEG3 and TNF-α. RESULTS: The expression of MEG3 and miR-181b in the peripheral blood of patients with Crohn's disease was remarkably associated with the rs322931 and rs7158663 polymorphisms. rs322931 (C>T) in miR-181b and rs7158663 (G>A) in MEG3 significantly promoted the expression of TNF-α, IL-1ß, IL-6, CRP, SSA, AAT, AAG and HPT. Luciferase assay demonstrated that miR-181b was capable of repressing the expression of MEG3 and TNF-α through binding to their specific binding sites. Moreover, alteration of MEG3 and miR-181b expression also showed a remarkable impact on the MEG3/miR-181b/TNF-α signaling pathway in THP-1 cells. CONCLUSIONS: In conclusion, our study demonstrated that two SNPs, rs322931 (C>T) in miR-181b and rs7158663 (G>A) in MEG3, could aggravate the inflammatory response of anal abscess in patients with Crohn's disease via modulating the MEG3/miR-181b/TNF-α signaling pathway.

Longest form of CCTG microsatellite repeat in the promoter of the CD2BP1/PSTPIP1 gene is associated with aseptic abscesses and with Crohn disease in French patients.

PURPOSE: Aseptic abscesses syndrome (AA) is an inflammatory disease in which non-infectious deep abscesses develop; these respond quickly to corticosteroids. AA is associated with Crohn disease (CD) in 57% of cases and with neutrophilic dermatosis (ND) in 20%. Pyoderma gangrenosum is usually a sporadic ND. A hereditary autosomal dominant syndromic kind of pyoderma gangrenosum, the PAPA syndrome, is linked to mutations in the CD2BP1/PSTPIP1 gene. We systematically screened this gene in French AA patients. RESULTS: One microsatellite (CCTG)n with 3 alleles was identified in the promoter. The longest form (CCTG)7 was significantly more frequent in AA patients than in French controls (P = 0.0154). We also found an association of the (CCTG)7 allele with CD in French patients (P = 0.0351). This association was not found in a sample of Indian patients. CONCLUSIONS: The CCTG repeat in the PSTPIP1 promoter may play a role in the pathogenesis of AA and of CD. Further investigations are required to demonstrate the possible modulation of gene expression by the (CCTG)n motif.

Extensive comedonal and cystic acne in Patau syndrome.

Patau syndrome is a chromosomal disorder associated with multiple malformations caused by inheritance of an extra chromosome (trisomy 13). Some skin defects have been reported in patients with Patau syndrome, such as scalp defects, glabellar stains, deep palmar creases, rocker-bottom feet, convex soles, hyperconvextity of the nails, and multiple hemangiomas. To our knowledge, widespread comedonal and cystic acne have not been previously reported in Patau syndrome.

Complete genome analysis of Glutamicibacter creatinolyticus from mare abscess and comparative genomics provide insight of diversity and adaptation for Glutamicibacter.

Bacteria of the genusGlutamicibacterare considered ubiquitous because they can be found in soil, water and air. They have already been isolated from different habitats, including different types of soil, clinical samples, cheese and plants. Glutamicibacter creatinolyticus is a Gram-positive bacterium important to various biotechnological processes, however, as a pathogen it is associated to urinary tract infections and bacteremia. Recently,Glutamicibacter creatinolyticusLGCM 259 was isolated from a mare, which displayed several diffuse subcutaneous nodules with heavy vascularization. In this study, sequencing, genomic analysis ofG. creatinolyticusLGCM 259 and comparative analyseswere performedamong 4representatives of different members of genusfromdifferent habitats, available in the NCBI database. The LGCM 259 strain's genome carries important factors of bacterial virulence that are essential in cell viability, virulence, and pathogenicity. Genomic islands were predicted for 4 members of genusGlutamicibacter,showing ahigh number of GEIs,which may reflect a high interspecific diversity and a possible adaptive mechanism responsible for the survival of each species in its specific niche. Furthermore,G. creatinolyticusLGCM 259 sharessyntenicregions, albeit with a considerable loss of genes, in relation to the other species. In addition,G. creatinolyticusLGCM 259 presentsresistancegenes to 6 differentclasses ofantibiotics and heavy metals, such as: copper, arsenic, chromium and cobalt-zinc-cadmium.Comparative genomicsanalysescouldcontribute to the identification of mobile genetic elements particular to the speciesG. creatinolyticuscompared to other members of genus. The presence of specific regions inG. creatinolyticuscould be indicative of their rolesin host adaptation, virulence, and the characterization ofastrain that affects animals.